Both calcined zircon sand and calcined zircon powder are natural zircon sand clinker imported from Australia and subjected to high-temperature calcination. After being held at a temperature above 1300 degrees for more than 12 hours, low-melting-point alkaline oxides such as Na and K, as well as organic matter, are ablated. This results in more stable physical and chemical properties, better refractoriness, and an extremely low thermal expansion coefficient. The presence of free SiO2 improves the creep resistance of the coating at high temperatures, while the rounded particles enhance the permeability of the coating, reducing the rate of sand adhesion defects and improving the surface finish of investment casting parts.